1. Field of the Invention
The present invention relates to a connector for electrically connecting circuit boards to each other.
2. Description of the Related Art
A plurality of printed wiring boards forming digital circuits are built-in within a relatively narrow space in an electronic equipment such as a cellular phone. The plurality of printed wiring boards are mutually connected electronically, for example, via a connector for connecting the circuit boards.
As shown in FIG. 9, the connector for connecting the circuit boards is comprised of a male connector section 4 disposed on a first printed wiring board 2 and a female connector section 6 disposed on a second printed wiring board 8 opposite to the first printed wiring board 2.
The male connector section 4 has, as main constituent elements, a base 4M molded of resinous material, and contact terminals 4Ai and 4Bi (i=1 to n; n is a positive integer) arranged at a predetermined distance on both ends of longer sides of the base 4M, respectively, to be electrically connected at one ends thereof to the respective electrodes of the first printed wiring board 2.
In a region between the contact terminals 4Ai and 4Bi in the base 4M, recesses 4a and 4b are formed at a predetermined distance between the both, to be engaged with projections 6a and 6b, respectively, of a connector section 6 described later.
Further, on each of both ends of shorter sides of the base 4M, a pair of nibs 4Na, 4Nb are provided. The pair of nibs 4Na, 4Nb are molded of resinous material to be integral with the base 4M. The pair of nibs 4Na, 4Nb are selectively engaged with the outer edge of through-holes 6Ha, 6Hb, respectively, of the female connector section when assembled to the female connector section 6.
The female connector section 6 has, as main constituent elements, a box-like base 6M having an accommodation portion for accommodating the base 4M of the male connector section 4 and the contact terminals 4Ai and 4Bi, and contact terminals 6Ai and 6Bi (i=1 to n; n is a positive integer) arranged at a predetermined distance on both ends of longer sides of the base 6M, respectively, to be electrically connected at one ends to the respective electrodes of the second printed wiring board 8.
Projections 6a, 6b are spaced at a distance in a region of the accommodation portion within the base 6M between the contact terminals 6Ai and 6Bi, to be engaged with the recesses 4a and 4b of the base 4M described above.
On the both ends of shorter sides of the base 6M, through-holes 6Ha and 6Hb are formed to be engageable with the pair of nibs 4Na and 4Nb when the male connector section 4 is assembled.
When this male connector section 4 is assembled to the female connector section 6 so that the first printed wiring board 2 is electrically connected to the second printed wiring board 8, as shown in FIGS. 10, 11 and 12, base 4M of the male connector section 4 is press-fit into the accommodation portion of the base 6M against the mutual elastic force between the contact terminals 4Ai, 4Bi and the contact terminals 6Ai, 6Bi. At this time, the recesses 4a and 4b in the base 4M are engaged with the projections 6a and 6b, respectively, as well as the pair of nibs 4Na and the pair of nibs 4Nb are engaged with the periphery of the through-holes 6Ha and the through-holes 6Hb, respectively, whereby the male connector section 4 is held by the female connector section 6.
When the assembly of the male connector section 4 and the female connector section 6 is built-in in the electronic equipment such as a cellular phone, in which the first printed wiring board 2 and the second printed wiring board 8 are electrically connected to each other as described above, there is a risk in that the male connector section 4 comes off from the female connector section 6 when an electronic equipment is subjected to the action of an impactive force caused by the dropping thereof.
This is because, as shown in FIG. 13 in an enlarged scale, the size of the engagement area between the nibs 4Na, 4Nb and the peripheries of the through-holes 6Ha, 6Hb, respectively, is designed to be relatively small for enhancing ease of the attachment/detachment of the male connector section 4 from the female connector section 6. Also, the pair of nibs 4Na and 4Nb molded of resinous material to be integral with the base 4M may readily deform by the impactive force, respectively.
Further, there is a risk in that the male connector section 4 does not securely keep hold of the female connector section 6 each other, since the nibs 4Na and 4Nb molded of resinous material are worn when the attachment/detachment described above is repeated.